>> I have a patch that removes these warnings.
>> Should I post it here or on emacs-devel?
>
> Please post here, and thanks.  If it turns out a more general
> discussion is needed, we will start it on emacs-devel then.

This new option was discussed many times on emacs-devel,
and here it's finally implemented.  As an example the patch
demonstrates the required changes only for markdown-ts-mode, and
similarly the same changes will be applied to all other ts-modes: